Mechanism for regulating filling feed



P 5, 1967 v c. F. LIBBY 3,339,590

I MECHANISM FOR REGULATING FILLING FEED Filed Oct. 14, 1965 3 Sheets-Sheet 1 E8 r-- lllllllllllllmlllllz g4 @wmr- 66 INVENTOR. FIG. I CARL F. LIBBY ATTORNEYS Sept. 5, 1967 c |BBY 3,339,590

MECHANISM FOR REGULATING FILLING FEED Filed Oct. 14, 1965 5 Sheets-Sheet 2 IT: I Emowoua u m INVENTOR.

CARL F. Ll BBY BY M Wwm ATTORNEYS Sept. 5, 1967 c. F. LIBBY MECHANISM FOR REGULATING FILLING FEED 3 Sheets-Sheet 3 Filed vOct. 14, 1965 FIG.5

INVENTOR. CARL F. LIBBY ATTORNEYS Patented Sept. 5, 1967 3,339,590 MECHANISM FOR REGULATING FILLING FEED Carl F. Libby, Stoughton, Mass, assignor to John D. Riordan, Hopkinton, Mass., and Gertrude Libby, Stoughton, Mass, trustees of the Libby family trusts Filed Oct. 14, 1965, Ser. No. 495,816 Claims. (Cl. 139-122) ABSTRACT OF THE DISCLOSURE In a narrow-web loom having a finger with a guide hole in the free end to project loops of weft yarn through the warp shed, the path of the weft yarn approaching the guide hole in the finger is varied so that the demand on the yarn source for weft yarn to enter the Warp shed is constant.

This invention relates to mechanism for regulating the feeding of filling yarn in a shuttleless loom for weaving narrow webs, the loom being characterized by the use of a finger having an eye in its free end by which a loop of filling yarn is projected through the shed of warp yarns, the end of each such loop being caught at the far side of the shed and retained as the finger is retracted from the shed so that the shed can be changed by the loom harness for the introduction of the next loop of filling by the finger. A loom of this type is illustrated in US. Patent No. 2,180,831, granted Nov. 21, 1939. For rapid operation of the loom the finger is actuated in such a way that the free end having the eye therein is made to move in a curved path, sweeping rapidly through the shed to the far side thereof where the loop of filling is caught, then being retracted from the shed near the fell of the fabric. Owing to the shape of the path traveled by the free end of the finger, the rate at which filling yarn is required at different stages of a loop-projecting cycle varies sharply and at one stage of the cyce is actually negative so that it has been necessary to provide a spring take-up in the filling feed to retract the slack that occurs in the loop of yarn during a part of the swing of the free end of the finger through the shed. This take-up results in a rapid variation in tension on the yarn which limits the speed at which the loom can be operated, especially when a very fine yarn is used as filling. As a practical matter, a loom cannot be profitably run at a speed which results in frequent breaking of the filling yarn.

According to the present invention, a filling yarn is supplied to the finger at a tension which is very light and is constant so that delicate yarns can be used when operating the loom at high speeds. This is done, as hereinafter explained, by drawing the yarn positively at a constant rate from the source thereof by a constant-feed device and arranging fixed guides for the yarn to cooperate with guide eyes in the finger in such a way that'the length of yarn from the constant feed device to the eye in' the free end of the finger is approximately invariable throughout each cycle of movement of the finger into and out of the warp shed.

In a shuttleless loom of the type referred to, the finger which thrusts the loops of the filling through the warp shed is operated so that its free end which has the eye through which the yarn extends moves initially in a nearly straight line alongside of the near side of the warp shed and in a rearward direction away from a starting point near the adjacent selvage at the fell of the fabric. The free end of the finger then swings quickly through the shed in an arcuate path to a point sufiiciently beyond the far side of the shed for the end of the yarn loop to be caught by a knitting needle near the fell of the fabric which is being woven. The free end of the finger then is retracted along length of yarn from the constant feeding device to an approximately straight line parallel to the fell of the fabric to its starting point. During the early part of its cycle along the near side of the shed and the beginning of the swing through the shed, the finger draws from the source of the filling yarn enough yarn to form a loop extending sufiicienty beyond the far side of the shed to be caught by the knitting needle there. There is thus a little excess yarn in the shed when the finger starts its retractive movement after the end of the yarn loop has been caught by the knitting needle. This excess must 'be withdrawn as the finger is being retracted so that the pick of Weft yarn will be straight when beat up by the reed immediately after the finger has been withdrawn from the shed. For this purpose it has been customary to use a spring take-up device which yields when the initial movement of the finger in a cycle makes a sudden demand for yarn from the supply source. This results in a rapid vibration of the spring take-up device and consequent rapid changes in the tension of the yarn, especially when the loom is operated at high speeds. Accordiny to the present invention most if not all of this oscillation of the tension on the yarn is obviated by the provision of fixed yarn guides cooperating with guide eyes on the finger to maintain the the eye in the free end of the finger invariable as the finger swings through its cycle.

For a more complete understanding of the invention, reference may be had to the following description thereof and to the drawings, of which FIGURE 1 is an elevational view of the constant feed device, an overhead yielding guide, the finger crank and the crank cover;

FIGURE 2 is an elevation, on a larger scale, of the constant feed device shown in FIGURE 1, as viewed from the right;

FIGURE 3 is a plan view of the crank cover, crank and finger;

FIGURE 4 is a diagram showing the variations in yarn demand by the finger during a cycle;

FIGURE 5 is a plan view of the crank cover shown in FIGURE 3, but with less additional detail; and

FIGURE 6 is a plan view of an auxiliary member for the crank cover.

A portion of the frame of a narrow-web loom is indicated at 20. A frustum of a cone 22 is mounted on a horizontal shaft 24 rotated at constant speed by the loom driving mechanism (not shown). A bracket 26 projects out from the frame 20 and is longitudinally adjustable thereon. To this bracket is adjustably secured a vertical plate 28 carrying a pivot 30 by which a horizontal bar 32 is rocka'bly supported. A freely turning roller 34 is carried by the bar 32 directly over and in contact with the cone 22. A spring 36 is attached to the bar 32 and connected to the plate 28 in such a way as to press the roller 34 against the surface of the cone 22. The bar 32 carries three yarn guides 38, 40, 42 to maintain the filling yarn F in the nip between the roller 34 and the cone 22. The yarn is thus drawn from the source (not shown) at a constant rate by this feeding device, the rate of feed being accurately cont-rolled by longitudinally adjusting the bracket 26 to bring the roller 34 into contact with a portion of the cone 22 of greater or lesser diameter according as an increase or decrease in the rate of feed is sought by adjustment.

As indicated in FIGURE 1, the yarn F is drawn from the yarn package or other source thereof by the feeding device, preferably through a tension device comprising a pair of disks 44 lightly pressed together by a weak spring wire 48 with an eye 50 at its free end through which the yarn from the guide 42 passes, the other end of the spring wire 48 being adjustably secured by thumb-nuts 52. Also secured to the bracket 46 is a piece 54 of electrical insulation on which is mounted a metal contact member 56 in a position to be touched by the wire 48 when there is no tension on the yarn through the eye 50. An electrically operated stop-motion device of any of the wellknown varieties (not shown) is connected in a circuit with the spring wire 48 and the contact member 56 to stop the loom when the yarn breaks.

From the eye 50 the yarn F goes to the finger 60 by which loops of the yarn are projected through the warp shed (not shown). The finger is actuated by a crank 62 which revolves about a crank shaft 64, one end of the finger 60 being rotatively mounted on the crank-pin 66. The finger extends through a finger guide 68 which is rockable about a vertical axis 70, the free end of the finger with an eye 72 in it extending beyond the guide 68. A housing 74 is mounted over the crank 62. In the top of the housing is a carefully shaped aperture 76 the edge 77 of which is rounded and smoothed to guide the yarn F which passes down from the overhead guide eye 50 through the aperture 76 to an eye 78 in an extension 80 of the finger 60. The yarn passes from the eye 78 to the eye 72 in the free end of the finger, running along beside the finger and through a guide notch 82 provided in the side of the finger guide 68 to keep the filling yarn from touching the Warp yarns in the shed.

The housing 74 is a convenient means for supporting the shaped guide edge 77 over the crank 62, but it is evident that other means could readily be employed for the same purpose.

The function of the edge 77 is illustrated in FIGURES 3 and 4 by a series of points numbered 1 to 12 at intervals around the crank axis 64. The points 10 to 4 are spaced 40 apart. The points 4 to 10 are spaced 20 apart as the curve 90 in FIGURE 4 changes rapidly between these points. The abscissae of the straight line 92 represent the steadily increasing length of the filling yarn from the constant feeding device to the fabric as the crank makes one revolution. The length a 11 etc. represent successive values of the changing length of the yarn extending from the adjacent selvage at the fell of the fabric to the eye 72 of the finger, as indicated in FIG- URE 3, as the crank makes a revolution and the finger sweeps through the shed, hooking the end of the yarn loop on a knitting needle at the far side of the shed. The lengths b b etc. represent successive values of the distances from the guide edge 77 to the eye 78 as the crank reaches the numbered points as it makes one revolution. The path described by the eye 78 is indicated in FIGURE by the broken line 94. The aperture 76 is shaped so that as the crank makes a revolution about its axis, the sum of the length of yarn between the edge 77 and the eye 78 and the length of the yarn between the fabric and the eye 72 of the finger will increase at the same rate as the delivery by the feeding device. As a result, during the operation of the loom there is little or no motion of the eye 50 which indicates that there is little or no variation in the light tension on the yarn. This permits the use of very fine yarns and rapid operation of the loom with little or no breakage of the yarn.

The shape of the edge 77 of the aperture 76 was developed for weaving a fabric of a certain width. If a wider or narrower fabric is to be woven, the demands for yarn as the finger is being retracted from the shed and the crank is passing the points 8 to 12, would be different. To make a ready adjustment of the shape of the aperture 76, an auxiliary plate 96 may 'be pivoted at 98 upon the top of the housing 74 and secured in a suitable position of angular adjustment. This auxiliary plate has a specially shaped edge 100 some of which becomes an active guiding edge when the plate is swung about its pivot to close part of the aperture 76.

The constant feed device is valuable when fine or weak yarn is used for filling. If a stronger yarn is used, it can be run from the tension device 44 direct to the tension eye 50, by-passing the constant feed device.

I claim:

1. In a narrow web loom having a finger with an eye in one end for filling yarn and means for actuating said finger to move said end to describe a closed curve, said actuating means comprising a finger guide through which the finger slidingly extends, said guide being rockable about a vertical axis, a crank with a pin to which the other end of the finger is operatively connected, said crank having a crankshaft rotatable about a vertical axis; a second guide eye carried by said finger at a point remote from the first said eye, a yarn guide member supported over said crank, said guide having an aperture the edge of which is engaged by a filling yarn traveling down from above the member and through said aperture to said second guide eye and on through the first said guide eye to said web, the shape of said aperture being such that the sum of the length of yarn from said edge to said second guide eye and the length of yarn from the first said guide eye to said web increases at a substantially constant rate during each cycle of operation of said finger.

2. Mechanism as described in claim 1, said finger having an extension from the crank pin in the direction away from said finger guide, said second guide eye being in said extension at a point spaced from the crank pin.

3. Mechanism as described in claim 1, and a device for feeding yarn at a constant rate to said yarn guide member.

4. Mechanism as described in claim 1, said yarn guide member being a housing enclosing said crank and having said aperture in the top thereof.

5. Mechanism as described in claim 1, and an auxiliary member adjustably supported on said yarn guide member and adjustably movable to modify the shape of said aperture.

References Cited UNITED STATES PATENTS MERVIN STEIN, Primary Examiner. H. JAUDON, Assistant Examiner. 

1. IN A NARROW WEB LOOM HAVING A FINGER WITH AN EYE IN ONE END FOR FILLING YARN AND MEANS FOR ACTUATING SAID FINGER TO MOVE SAID END TO DESCRIBE A CLOSED CURVE, SAID ACTUATING MEANS COMPRISING A FINGER GUIDE THROUGH WHICH THE FINGER SLIDINGLY EXTENDS, SAID GUIDE BEING ROCKABLE ABOUT A VERTICAL AXIS, A CRANK WITH A PIN TO WHICH THE OTHER END OF THE FINGER IS OPERATIVELY CONNECTED, SAID CRANK HAVING A CRANKSHAFT ROTATABLE ABOUT A VERTICAL AXIS; A SECOND GUIDE EYE CARRIED BY SAID FINGER AT A POINT REMOTE FROM THE FIRST SAID EYE, YARN GUIDE MEMBER SUPPORTED OVER SAID CRANK, SAID GUIDE HAVING AN APERTURE THE EDGE OF WHICH IS ENGAGED BY A FILLING YARN TRAVELING DOWN FROM ABOVE THE MEMBER AND THROUGH SAID APERTURE TO SAID SECOND GUIDE EYE AND ON THROUGH THE FIRST SAID GUIDE EYE TO SAID WEB, THE SHAPE OF SAID APERTURE BEING SUCH THAT THE SUM OF THE LENGTH OF YARN FROM SAID EDGE TO SAID SECOND GUIDE EYE AND THE LENGTH OF YARN FROM THE FIRST SAID GUIDE EYE TO SAID WEB INCREASES AT A SUBSTANTIALLY CONSTANT RATE DURING EACH CYCLE OF OPERATION OF SAID FINGER. 